The FUNCTION clause specified in the declaration topic defines and names a subfunction local to that block.
The term block refers to the SPL block structure consisting of an optional declaration topic, a mandatory executable section, and an optional exception section. Blocks are the structures for standalone procedures and functions, anonymous blocks, subprograms, triggers, packages, and object type methods.
The phrase the identifier is local to the block means that the identifier (that is, a variable, cursor, type, or subprogram) is declared within the declaration section of that block and is therefore accessible by the SPL code within the executable section and optional exception section of that block.
Subprocedures can only be declared after all other variable, cursor, and type declarations included in the declaration section. ( That is, subprograms must be the last set of declarations.)
PROCEDURE name [ (parameters) ]{ IS | AS }
[ PRAGMA AUTONOMOUS_TRANSACTION; ]
[ declarations ]
BEGIN
statements
END [ name ];
Argument | Description |
---|---|
name | name is the identifier of the subprocedure. |
parameters | parameters is a list of formal parameters. |
data_type | data_type is the data type of the value returned by the RETURN statement of the function. |
PRAGMA AUTONOMOUS_TRANSACTION | PRAGMA AUTONOMOUS_TRANSACTION is the directive that sets the subfunction as an autonomous transaction. |
declarations | declarations are variable, cursor, type, or subprogram declarations. If subprogram declarations are included, they must be declared after all other variable, cursor, and type declarations. |
statements | statements are SPL program statements (the BEGIN - END block may contain an EXCEPTION section). |
Examples
The following example shows the use of a recursive subfunction:
DECLARE
FUNCTION factorial (
n BINARY_INTEGER
) RETURN BINARY_INTEGER
IS
BEGIN
IF n = 1 THEN
RETURN n;
ELSE
RETURN n * factorial(n-1);
END IF;
END factorial;
BEGIN
FOR i IN 1..5 LOOP
DBMS_OUTPUT.PUT_LINE(i || '! = ' || factorial(i));
END LOOP;
END;
The output from the example is as follows:
1! = 1
2! = 2
3! = 6
4! = 24
5! = 120